The Tri-ethnic Center for Study of Drug Abuse Prevention is designed to be a national resource for drug abuse prevention research for Native-American, Mexican-American, and western White-American youth. It will be a primary access point for scientists and policy makers for data on epidemiology and etiology. It will engage in research on the etiology of youth drug use, studying both the general population of school-based youth and high risk groups such as dropouts and delinquents. It will explore the social, psychological and cultural underpinnings of drug abuse in both cross-sectional and longitudinal studies. The Center will be engaged in building and testing theories and models and assessing their implications for prevention. It will focus particularly on comparing and contrasting results across three ethnic groups, identifying similarities and differences that are important for prevention. The Center will design both community-wide prevention programs and special programs targeted at high risk youth. It will evaluate those programs, using random assignment designs and assessing process and outcome. It will be a source of solid and current information on the state of the art; determining what prevention programs are occurring in Mexican-American and Native-American communities, and presenting a series of conferences to give research scientists an opportunity to evaluate what is known and to suggest further research agendas. It will be heavily involved in dissemination; publishing in scien- tific journals and journals of practitioners, and presenting findings to field professionals in presentations and workshops. The Center will help to set the stage for the future of prevention research by providing research training opportunities for minority post-doctoral and doctoral students.